Multiline signal cable connectors such as the common D-SUB series are conventionally of a type in which a plurality of thin male pins (for example, 9, 15, 25, 37 or 50 thin male pins) extend axially through a cavity formed by a protective shield or wall into which a female plug with an equal number of sockets is inserted. In order to reliably make good contact for low-voltage signals, the contacting elements may be gold-plated or otherwise treated. The female sockets are usually formed as leaf springs which receive the pins in frictional engagement.
Connectors of this type are not meant to be mated and unmated very often, and in fact their typical life expectancy is about 500 mating cycles. Failure usually occurs because the frictional engagement damages one or more components of the connector, for example, wears the plating off or damages the pins or leaf springs.
It is often necessary, however, as for example in test equipment, rotating-head fabricating machines, etc., to connect and disconnect signal cables dozens or hundreds of times per day. In the past, this has required very frequent connector replacement or the use of expensive specially designed pairs of connectors strong enough to withstand such usage.